package com.nuoyuan.wx.common.utils;

import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

/**
 * @Author linus
 * @Date 8/3/18 : 14 : 22
 * @ProjectName robot
 * @Package com.exchange.robot.common.util
 * @Description
 */
@Component
public class SpringContextHolder implements ApplicationContextAware {


    private static ApplicationContext applicationContext;

    /**
     * 实现ApplicationContextAware接口的context注入函数, 将其存入静态变量.
     */
    public void setApplicationContext(ApplicationContext applicationContext)
    {
        SpringContextHolder.applicationContext = applicationContext;
    }

    /**
     * 取得存储在静态变量中的ApplicationContext.
     */
    public static ApplicationContext getApplicationContext()
    {
        checkApplicationContext();
        return applicationContext;
    }

    /**
     * 从静态变量ApplicationContext中取得Bean, 自动转型为所赋值对象的类型.
     */
    @SuppressWarnings("unchecked")
    public static <T> T getBean(String name)
    {
        checkApplicationContext();
        return (T) applicationContext.getBean(name);
    }

    private static void checkApplicationContext()
    {
        if (applicationContext == null)
        {
            throw new IllegalStateException("applicaitonContext未注入,请在applicationContext.xml中定义SpringContextUtil");
        }
    }
}
